The present invention generally relates to a transfer ribbon feed means and more particularly, to a transfer ribbon feed arrangement including a transfer ribbon tension unit, which is employed, for example, in a thermal transfer type recording apparatus.
Conventionally, in a thermal transfer type recording apparatus, for example, a thermal transfer printer employing a transfer ribbon such as inked ribbon therein, wrinkles of the ribbon, shears in printing or the like have been prevented in a manner wherein tension is applied to the transfer ribbon by winding it around a take-up roller connected to a driving source, with friction being applied by a shaft of a transfer ribbon feed roller.
Furthermore, with respect to a colored transfer ribbon, the color of each colored layer or the position thereof has been detected in a manner wherein markers are formed on the colored transfer ribbon at the portions subjected to no interference from printing and these markers are detected by an optical detecting means such as a photosensor composed of a light emitting diode and a phototransistor.
However, the transfer ribbon which is would around the feed roller and is rolled around the take-up roller has roll diameters which vary with the transportation thereof, and the tension applied on the transfer ribbon cannot be kept constant. Accordingly, wrinkles occur in the transfer ribbon, and shears or the like in printing still disadvantageously taken place.
In addition, the color of each colored layer or the position thereof has not been clearly detected in some cases due to an improper positioning of any colored layer of the colored transfer ribbon which results from a slackening of the ribbon or the like.